Short answer - Get a good project manager on your team :)
But I understand you don't always have the luxury to get a proj. mgr for a product launch. In some cases, for bigger launches, I have asked for a shared proj. manager from another team (especially the product team). If nothing - you basically have to wear two hats. I find it very hard and time-consuming because it takes me away from my PMM work, but it is a key role and someone has to do it diligently. I also use proj. management tools, don't have a preference here (asana, jira,...whatever rocks your boat)
I have used a number of applications in the past to project manage product launches. You can use Trello, Kapost, or even Excel.
The key to driving sucess is alignment across marketing groups and other teams. I set up weekly meetings where we go over set agenda items and deliverables. Frequently touching base with team members allows you as the launch manager to find out if there are bottlenecks that will affect the launch.
Ideally, it's a combination of the GM, product management and product marketing. The GM would set the overall business goals for the year or quarter including revenue. The PM often drives the product launch adoption and revenue goals for that product. PMM often builds the plan with the metrics to help back into those goals.
The important thing is that if you see a gap, make sure that someone is owning all of these goals, otherwise, it will be meaningless to have launch metrics.
I think you’re asking if it’s behind a pay wall and not just a free product? If that’s the case, you need material (video!) that can act as a demo, people want to see product, not just read about it. Salespeople who can give great demos and free trials are often a really effective a launch tool.